In the field of applied electrochemistry, various designs of electrolyzers including a diaphragm have been used for obtaining products by the anode oxidation of brine. The most widely used electrolyzers for this purpose contain an asbestos-based diaphragm. For example, see USSR Author Certificate N. 669764, dated 1976.
The main disadvantage of using an asbestos diaphragm is its relatively short useful life. The characteristics of these asbestos diaphragms also change over time, which requires special steps (such as special additives in the brine, a differential between the level of anolyte and catholyte, etc.) to maintain a stable regime for the electrolysis. Another disadvantage of using an asbestos diaphragm is the low purity obtained in the end products.
High purity end products of the electrolysis of brine can be obtained by using an ion-exchange membrane. For example, see USSR Author Certificate N. 1823884, dated 1988. However, using an ion-exchange membrane requires a careful purification of brine which adds additional expenses to the procedure. Power consumption for ion-exchange membranes is also high.
The most similar technology to the present invention is a device used for obtaining anode-oxidized products (including gases). Such a device contains electrodes that are nonsoluble during the electrolysis and such device also uses a cylindrical ceramic diaphragm. The cylindrical ceramic diaphragm can be manufactured, for instance, from non-enameled porcelain (see USSR Patent N. 43585, dated 1940) and the placement of the cylindrical ceramic diaphragm divides the inter-electrode space in the electrode chambers.
This device also contains structure for the circulation of brine through the electrode chambers and structure for removing the end products created during the use of the apparatus.
The beneficial characteristics of ceramic diaphragms are known. For instance, ceramic diaphragms keep their form during use and ceramic diaphragms possess high chemical resistance. However, they have been used only in laboratory-type electrolyzers due to high power consumption required. Ceramic diaphragms are displaced for industrial application by other types of diaphragms, for instance, by MIPOLAM.RTM. (a product of Huls Troisdorf Aktiengesellschaft) (a polymeric membrane).
The object of the present invention is to provide a simplified design of the apparatus and to make it possible to obtain high current efficiency of the gaseous products by the electrolysis of water-dissolved chloride of alkaline or alkaline-earth metals. It is a further object of the present invention to reduce the power consumption of the apparatus during use and to increase the service life of the apparatus as well as to make it possible to assemble an apparatus with required production capacity by putting together a number of cells. The end product produced using the apparatus of the present invention can be obtained either as a mixture of gases or as water-dissolved oxidants.